try to do sth.设法做某事,尽力做某事：He tried to finish the work ahead of time.
他设法提前完成这件工作.
try doing sth.试着做某事,试验做某事：
-I usually go there by train.
-Why not try going by boat for a change?(MET92)
--我通常乘火车去那儿.--为什么不换乘船呢?
try to do侧重尽力,为了达到目的而努力.try doing 只是一种新的尝试,并没有一定明显的目的性.据的例子可以清楚的说明